* Makefile.am: added config.h.windows
	* README.mingw: added more specific informations
	* README.windows: fixed project link
	* config.h.windows: create. use it to compile on mingw
	* configure.in: changed to release 6.1
	* src/boards/Makefile.am: added boards2static.pl utility for mingw
	* src/gcompris/assetml.c: (assetml_get_locale): replaced getenv by g_getenv
	* src/gcompris/board.c: (init_plugins), (board_check_file): merged mingw version and linux version
	* src/gcompris/gameutil.c: (gcompris_read_xml_file),
	(gcompris_load_menus): fixed bugs in which you cannot go back to upper menu if you enter
	the configuration dialog while you are in a submenu.
	* src/gcompris/gcompris-board.h: reindent
	* src/gcompris/gcompris.c: (setup_window), (gcompris_init): implemented the grace period stuff for
	mingw